1. Technical Field
The present invention relates to a connection structure of a crimp terminal with respect to wire, with waterproof performance.
2. Background Art
Weight reduction of a vehicle significantly affects fuel economy improvement. At the present when reduction in carbon dioxide emissions is required, a wire made of a lightweight aluminum or an aluminum alloy is advantageously used in a wire harness, specifically in an electric vehicle or a hybrid vehicle in which the wire harnesses are used in large quantity compared to a gasoline vehicle. However, in a state where an aluminum wire configured of aluminum or an aluminum alloy is crimped and connected to a terminal configured of copper or a copper alloy, if water is interposed in a contact portion of the two, the water acts as an electrolytic solution between different kinds of metals. If different kinds of metals of the copper terminal and the aluminum conductor become an electrical circuit through the electrolytic solution, because of difference in corrosion potential of the two, corrosion of a metal (for example, aluminum conductor) of less noble potential is accelerated. That is, galvanic corrosion occurs.
Thus, a crimp terminal in which occurrence of electrolytic corrosion can be prevented while ensuring conductivity even if the crimp terminal is configured of different kinds of metals for the wire conductor that is crimped by a barrel piece is proposed (see JP-A-2013-80682).
An example of a connection structure of the crimp terminal with respect to the wire of the related art described in JP-A-2013-80682 is illustrated in FIGS. 20 to 22. In the drawings, a direction toward a counterpart terminal that is one side of the terminal in a longitudinal direction (consistent with a longitudinal direction of the wire) is referred to as forward, the opposite direction thereto is referred to as backward, a side on which the wire is mounted on the crimp terminal is referred to as upward, the opposite direction thereto is referred to as downward, one side and the other side of the terminal forward in a width direction are referred to as a left side and a right side, respectively.
As illustrated in FIG. 20, a crimp terminal 110 has a box section (electrical connection section) including a spring piece 112 for connecting to a mating male terminal in a front portion made of copper or a copper alloy and has a wire connection section 120 that is crimping an end portion of a wire W in which a conductor Wa is made of aluminum or an aluminum alloy in a rear portion thereof. The wire connection section 120 has a conductor crimp section 121 that is crimped onto a conductor exposed section Wap in which a cover Wb of the end portion of the wire W is removed and the conductor Wa is exposed in a position of the front side, and has a cover crimp section 122 that is crimped onto a portion to which the cover Wb remained in the end portion of the wire W is attached in a position of a rear side thereof.
The conductor crimp section 121 and the cover crimp section 122 have a common bottom plate section 125, and a pair of left and right common caulking pieces 126 and 127. The caulking pieces 126 and 127 are erected upward from left and right side edges of the common bottom plate section 125, and caulk the conductor exposed section Wap and the portion to which the cover Wb is attached by being bent inwardly so as to surround the conductor exposed section Wap and the portion to which the cover Wb is attached of the wire W that is to be connected in a state where the conductor exposed section Wap and the portion to which the cover Wb is attached come into pressed contact with an upper surface of the bottom plate section 125. The wire connection section 120 is formed having a cross section of a U shape that is continuous from a front end of the conductor crimp section 121 to a rear end of the cover crimp section 122. Furthermore, the wire connection section 120 is configured having a length continuously and integrally covering from a portion on the front side from a front end Wap1 of the conductor exposed section Wap to a portion on the rear side from a front end Wb1 of the portion to which the cover Wb is attached, in a state of being crimped onto the end portion of the wire W.
Then, as illustrated in FIG. 20, a connection structure of the crimp terminal 110 with respect to the wire W is configured such that the conductor exposed section Wap of the end portion of the wire W is disposed on the wire connection section 120 in a state where a waterproof sheet 130 is disposed in a frame shape on an inner surface of the wire connection section 120. Furthermore, as illustrated in FIG. 21, the pair of left and right caulking pieces 126 and 127 caulk round inwardly. Furthermore, as illustrated in FIG. 22, an opening 128 that is the front end of the wire connection section 120 prevents infiltration of moisture by crushing and closing the front end of the wire connection section 120, and occurrence of galvanic corrosion of the conductor Wa is prevented when the crimp terminal 110 is configured of different kinds of metals.